Clay minerals are mineral particles having a particle diameter of 0.002 mm or less, and it is known that spreading the surface area of fine particles of 1 g results in an area as wide as a volleyball court.
This is because many pores are formed therein. It has been disclosed a feed manufacturing technology for serving as an adsorption of the microorganism or as a carrier of various functional materials by using these pores.
Parts of the pores existed in the inside of the feeds using common clay minerals are in communication with the outside thereof. Also, other parts of the pores are independently existed therein. Since the amount of the pores independently existed therein is not much in comparison with the total weight of the feed, it is difficult to provide a flowability thereof.
That is, it is difficult to prepare a floating feed for fish through the general feed manufacturing technology using the clay minerals.
Among the feed manufacturing technologies using the clay minerals, a patent application titled “Granule type macsumsuk feed additive and method for preparing the same” (Korean Patent Registration No. 10-0573811, filed Apr. 18, 2006) discloses a technology for preparing the livestock feed using the macsumsuk as the clay minerals.
The above patent discloses that macsumsuk and water are mixed to obtain a slurry, to which calcium carbonate is then mixed, and then the mixture is introduced into a granulator, and the prepared granules are calcined.
However, bubbles inside the granule come out for a short period of time due to high temperature in the procedure of molding and calcining of granules, resulting in a ring-shaped granule having a groove formed in one side thereof as shown in FIG. 1.
When being used as a general livestock feed, the ring-shaped granule having a groove does not cause any problem. Rather, as shown in the above patent, the ring-shaped granule serves as a carrier suitable for microorganism culturing, thereby providing good-quality feed.
However, in the case where this structure is put in water, the groove is filled with water, and thus the granule sinks for a short period of time due to the weight of water.
Thereby, this structure is appropriate as a precipitation feed, but is not an appropriate shape as an extruded feed.
Moreover, the existing inorganic substances using natural minerals for addition of fish feed are mixed with a fish feed after a pulverizing process, and thus, are not uniform in terms of the shape and size of particles, have no floating property of materials and deteriorated fluidity, and precipitate.
For this reason, a feed which is in a floating state for a predetermined time in water while having excellent effects of macsumsuk, and thus is suitable to be used as an extruded feed needs to be developed as shown in the patent document below.
Meanwhile, the “method for developing an agricultural and livestock fertilizer enriched with iron using blood of livestock and an antibiotic-free feed (Korean Patent Publication No. 10-2008-0040296, filed May 8, 2008) discloses a technology in which the blood of livestock is sterilized and processed, and then mixed with organic substances, in organic substances, and microorganism agents, and the mixture is used to prepare a fertilizer or a feed for producing agricultural and marine products.
The above patent discloses that the blood and other additives are mixed and homogenized, and then extruded and molded into pellets.
As such, technologies of reutilizing the blood helpful for growth of livestock as a feed raw material are currently disclosed, but according to the technologies, the organic and inorganic substances are simply mixed, extruded, and molded.